The present invention generally relates to a copy sheet stack apparatus in which copy paper sheets discharged from an image-forming device such as copying apparatus are accommodated, stacked and bound by a stapler.
Commonly, as examples of a copy sheet stack apparatus for accommodating copy sheets, there have been proposed, for example, in Japanese Laid-open Patent Publication Nos. 59-43765 and 60-183461, an apparatus which is generally called as finisher and is constructed so that copy sheets are stacked onto a tray to be arranged and bound by means of a staple and thus are moved therefrom to a stack unit to be stacked and accommodated thereinto. Then, in these constructions, the apparatus include a movable member for moving bundles of the copy sheets to the stack unit. That is, the apparatus in 60-183461 includes a belt for driving to swing and rotate, the belt serving as the tray and the apparatus in 59-43765 includes a pinch roller and a discharging roller, each member being driven for rotation thereof.
In the above apparatus, however, there have been some problems. That is, in the apparatus having the rollers, there has been such a problem that since the rollers are disposed to be capable of advancing and retreating so as to be driven only when the copy sheets are discharged, the apparatus is complex in mechanism. In the apparatus having the belt, there has been such a problems that since the belt is disposed to be capable of swinging, the apparatus is complex in mechanism and is required to form a very large dead space for swinging the belt.
Meanwhile, there has been proposed another kind of apparatus to be simple in mechanism in which each bundle of the copy sheets is fallen by its own weight from the tray while sliding. However, in the another apparatus, it is because each copy sheet passed through a fixing device intends to curl that it is difficult to make the copy sheets arrange and stack into the stack unit only by free falling of the copy sheets.